swap/upgrades to front calipers

[dagen_1]

This is just personal opinion, but I think you should upgrade to HD spindles first. There was a reason GM did this-first on the EC, and then on the rest of the line.

i just bought new drop spindles

maybe one of these days...

 

[woody80z28]

larger bore just requires more fluid, have better brakes by swapping to a bigger bore master than you would just changing calipers, you still only have the 1/2 ton rotor size that have less surface area for stopping vs the bigger 9.25 ifs front rotors

This is incorrect. Larger caliper pistons create more clamping force. And larger piston master cylinders create less pressure given a constant input force. It's all about PSI.

Think of it this way using simple numbers: If you put 100lbs of force on the pedal (at 5:1 ratio) with a master cylinder that has 1 square inch of area, you have 500psi in the brake line. Let's say the front caliper has 5 square inches of area. Now you have 2500psi of pressure at the caliper squeezing the rotor. Now let's say the master cylinder has 2 sq in of area...you're cutting your pressure in half because that 500lbs of pressure is spread over 2 sq in.

Surface area basically only matters for pad & rotor life. Brake torque comes from the pressure being applied by the caliper, and the leverage in relation to the wheel center. For example, a 12" rotor has 20% more leverage than a 10" rotor because the caliper is 6" from the center rather than 5".

So in actuality, bigger calipers and a smaller master cylinder will create more brake torque. However, this hydraulic advantage comes at the cost of a longer pedal travel.

Hydroboost is a good way to increase pressure without increasing pedal. I did it on my truck last year and I love it. I also have 1 ton calipers.

 

[tylers88]

how different are the GMT400 and GMT800 knuckles, i plan on running 35x12.50R18s(at the smallest) on my 88 and I dont trust the stock brakes with my 31s. I was think about seeing if the 05+ 1/2 front disks would swap over. I might need to go put the bracket and rotor off my dads truck now.

 

[Darkrider]

This is incorrect. Larger caliper pistons create more clamping force. And larger piston master cylinders create less pressure given a constant input force. It's all about PSI.

Think of it this way using simple numbers: If you put 100lbs of force on the pedal (at 5:1 ratio) with a master cylinder that has 1 square inch of area, you have 500psi in the brake line. Let's say the front caliper has 5 square inches of area. Now you have 2500psi of pressure at the caliper squeezing the rotor. Now let's say the master cylinder has 2 sq in of area...you're cutting your pressure in half because that 500lbs of pressure is spread over 2 sq in.

Surface area basically only matters for pad & rotor life. Brake torque comes from the pressure being applied by the caliper, and the leverage in relation to the wheel center. For example, a 12" rotor has 20% more leverage than a 10" rotor because the caliper is 6" from the center rather than 5".

So in actuality, bigger calipers and a smaller master cylinder will create more brake torque. However, this hydraulic advantage comes at the cost of a longer pedal travel.

Hydroboost is a good way to increase pressure without increasing pedal. I did it on my truck last year and I love it. I also have 1 ton calipers.

The truck I want to do this to already has hydraboost (diesel 1500) so I guess im getting new 1 ton calipers soon.

Powered by Detroit Diesel

 

[nascarguy320]

So I have a 97 Tahoe 4x4 and I tow all the time and I am looking at new brakes now can I do this on my truck the larger calipers and pads, and I would like a list of parts that I would need to do this. My truck is my DD with that said I need a better braking system soon....

 

[bluex]

Ya just look up a 97 3500 4x4 an order calipers for that. If your pads are good you can reuse them. The pad that goes in the caliper you will just have to spread the clip out so the pad fits snugly into the caliper piston.

 

[nascarguy320]

Ok thanks for the info, looking them up now...

 

[Sparg93]

As Woody eluded to, there is ZERO benefit to actually buying bigger calipers. If you keep everything else the same and put a caliper with a bigger bore on it, you're actually increasing your pedal travel...and your stopping distance will worsen. I did a full writeup on this subject on GMC4x4 with brake distances measured.

To fully realize the benefits of 3/4t calipers, you must upgrade to hydroboost b/c as Woody said, it's all about PSI. As an example, a stock vacuum system generates about 800psi at the caliper and hydroboost generates 1200psi. If you swap up to 3/4t or worse, 1t calipers on a vacuum system, you're going to create <800psi at the caliper for a given amount of pedal travel.

If you already have hydroboost and you'd like to purchase larger calopers, you will still see WORSE results then keeping the stock ones on. To realize the benefit of these larger calipers, you will have to pair this to the appropriate sized hydroboost and PS pump...and yes, there are different PS pumps and hydroboost units for the various caliper sizes.

I hope this helps!

 

[guybb3]

This is incorrect. Larger caliper pistons create more clamping force. And larger piston master cylinders create less pressure given a constant input force. It's all about PSI.

Think of it this way using simple numbers: If you put 100lbs of force on the pedal (at 5:1 ratio) with a master cylinder that has 1 square inch of area, you have 500psi in the brake line. Let's say the front caliper has 5 square inches of area. Now you have 2500psi of pressure at the caliper squeezing the rotor. Now let's say the master cylinder has 2 sq in of area...you're cutting your pressure in half because that 500lbs of pressure is spread over 2 sq in.

Please be patient with the Newbie but I don't get this. With hydraulic wood splitters, the pumps usually put out about 2,000 psi. The ton rating is derived from the piston diameter that the pressure is applied to. The bigger the piston, the larger the pressure. I would think 500 lbs applied to 2 sq in would be 2 times the pressure that 1 sq in would be due to surface area????

 

[HRV-LS1]

Has anyone just tried swapping to the 1 ton calipers. No hydroboost, just the 1 ton calipers? If so, how do they stop, better, same, or worse?